陡坡—岩溶耦合作用下公路桥梁桩基极限承载力的计算  

Calculation of Ultimate Bearing Capacity of Pile Foundations of Highway Bridges under the Coupling of Steep Slope and Karst

作　　者：冯忠居[1] 武敏 何静斌 黄骤屹 董芸秀 胡海波 尹继兴 FENG Zhong-ju;WU Min;HE Jing-bin;HUANG Zhou-yi;DONG Yun-xiu;HU Hai-bo;YIN Ji-xing(School of Highway,Chang'an University,Xi'an 710064,China;Wenshan Guangna Expressway Investment Construction Development Company Limited,Wenshan 663000,China;School of Civil Engineering,Longdong University,Qingyang 745000,China)

机构地区：[1]长安大学公路学院,西安市710064 [2]文山州广那高速公路投资建设开发有限公司,文山州663000 [3]陇东学院土木工程学院,庆阳市745000

出　　处：《公路》2021年第1期115-121,共7页Highway

摘　　要：为研究陡坡—岩溶耦合作用对桩基竖向承载特性的影响,基于现行规范中的桩基极限承载力标准值公式,采用Marc有限元软件对4种顶板厚度、5种坡度进行正交模拟试验,分别提出了针对顶板厚度和坡度对于桩基竖向分项承载力的修正系数。试验结果表明,桩基极限承载力随坡度增大而逐渐减小,坡度大于45°时,减幅达到29.83%;当顶板厚度大于3倍桩径后,继续增加顶板厚度对桩基极限承载力的提高效果不大,稳定在19%左右。根据计算结果分析桩基竖向分项承载力占比的变化规律,提出了同时考虑顶板厚度和坡度的桩基竖向极限承载力标准值的计算公式以及修正系数αi、β。In order to study the influence of steep slope-karst coupling on the vertical bearing characteristics of pile foundations,based on the standard value formula of ultimate bearing capacity of pile foundations in the current code,Marc finite element software is used to perform orthogonal simulation tests on four kinds of roof thicknesses and five kinds of slopes.Correction coefficients for the vertical subitem bearing capacity of the pile foundation are proposed for the thickness and slope of the roof.The test results show that the ultimate bearing capacity of the pile foundation gradually decreases with the increase of the slope.When the slope is greater than 45°,the reduction reaches 29.83%.When the thickness of the roof is greater than 3 times the diameter of the pile,increasing the thickness of the roof to improve the bearing capacity of the pile foundation is not significant,and the stability is about 19%.According to the calculation results,the variation rule of the vertical sub-bearing capacity of the pile foundation is analyzed,and the calculation formula of the standard value of the vertical ultimate bearing capacity of the pile foundation considering the thickness and slope of the roof is also proposed,as well as the correction coefficient and.

关 键 词：岩土工程 桩基 陡坡—岩溶 正交数值模拟 承载力 修正系数 计算 

分 类 号：U441.4[建筑科学—桥梁与隧道工程]